The prolonged closure of nuclear reactor 3 at Hunterston B in North Ayrshire, UK

Hunterston B NO2NuclearPower 22 June 18 THE prolonged closure of reactor 3 at Hunterston B in North Ayrshire is the beginning of the end for seven nuclear power stations in Scotland and England. The reactor is scheduled to stay offline until 17th November according to EDF’s website, but experts doubt whether it will ever restart, and argue that proliferating cracks in other elderly reactors across the country will shorten their expected lives and lead to premature shutdowns. EDF Energy, however, insist that it will be able to reopen the reactor.

Independent nuclear engineer John Large says extending the life of troubled reactors like the one at Hunterston is “gambling with public safety”. He says the new cracks signal the “death knell” for Hunterston reactor three. “This means that reactor four is doomed to the same fate, followed by similar plants at Hinkley Point and Hartlepool, thereafter progressively followed by other advanced gas-cooled reactors”.

EDF says it has found a total of 39 “keyway root cracks” in the reactor and they are “happening at a slightly higher rate than modelled”. The integrity of the thousands of graphite blocks that make up the reactor core is vital to nuclear safety. They ensure that the reactor can be cooled and safely shut down in an emergency. Large argues that EDF’s decision to keep reactor three closed until the end of the year was prompted by the UK Government’s safety watchdog, the Office for Nuclear Regulation (ONR). “ONR’s doubts about the reactor safety have not been satisfied by this most recent inspection,” he said. “It may simply be a way of saving face and fobbing off the announcement that the plant is to be permanently shut down.”

Large also highlighted the uncertainties in tracking cracks, which are mostly modelled rather than measured. “There is little that EDF can do to physically resolve this problem,” he said.

Rita Holmes, a local resident who chairs the Hunterston site stakeholder group, argued it would be very difficult for the public to have confidence in the safety of reactor three. “It has had its day and should be allowed to bow out gracefully,” she said. (1) “The local communities are unhappy that the reactor has any cracks, and certainly not happy that one with a growing number of cracks could be allowed to continue generation.”

If the graphite blocks fail and become misshapen, nuclear fuel could get stuck overheat, melt down and leak radioactivity in a major accident. Cracks could also prevent control rods from being inserted causing the nuclear fuel to overheat, potentially resulting in a nuclear accident. An ONR spokesperson said: “Before we grant permission to EDF to restart reactor three we will require that an adequate safety case justifying further operation.”. John Large said “The core at Hunterston may now be in such a poor structural state that its collapse during a relatively modest earthquake could result in a nuclear fuel meltdown and significant radioactive release.”

EDF says “We have prepared well for this; we have a £100 million graphite research programme.”” Professor Paul Bowen, a metallurgist from the University of Birmingham who advises the ONR, thought that the body was likely to insist on more frequent inspections rather than reactor closure. “I’m absolutely confident that the regulator will take a very conservative position,” he said. (2)

“The thing which will close (these reactors) down in the end will be the cost of ensuring safety. It is possible to make a safety case for a significant amount of cracked bricks but it takes time and costs money,” said Barry Marsden, professor of nuclear graphite technology at the University of Manchester. (3)

Local communities should be given a say in the future of Hunterston, according to Green MSP Ross Greer. He says the lack of public consultation has been unacceptable, while highlighting that European law says all ageing nuclear power stations should have an environmental impact assessment. He said: “This is obviously of major safety and economic concern to the local community. Last year I published a report urging the Scottish Government to review safety conditions at the site following earlier reports of cracks and the repeated granting of lifetime extensions to the plant. The local community currently has no say in decisions to extend a plant’s lifetime as an Environmental Impact Assessment with a public consultation is not required. The government must reconsider its position on the need for an Environmental Impact Assessment to accompany decisions on the granting of lifetime extensions to ageing nuclear power stations and commit to a renewed transition plan for North Ayrshire which will prevent the community being left behind, as so many others have been, by the closure of aging power stations.” (4)

A Committee of the Aarhus has just published a report which says the Netherlands “failed to comply” with Aarhus Convention by refusing to organise a public consultation on the 20 year lifetime extension of an old nuclear plant at Borssele. This has important implications for Torness which is due to submit its next Periodic Safety Review to the Office for Nuclear Regulation in January 2019.

(5) Experts estimate the 40% cut in the power station’s output – it normally supplies enough electricity for 1.8m homes – will cost the French state-owned firm £100m-120m in lost revenue. That is small compared with the impact of temporary safety closures at EDF’s French plants, which led profits to fall 16% last year, but it is still a blow the company could do without as it ramps up construction of the £20bn Hinkley Point C nuclear power station in Somerset. (6)

As things currently stand the UK’s remaining 8.9 GW of nuclear capacity will close over a 12-year period, starting in 2023. However, rather than wondering if the AGRs could be given further life extensions, questions should now be asked about the supply implications if some, or all, of the AGRs are unable to operate as envisaged, says Anthony Froggatt of Chatham House. With Brexit raising questions about the financing and schedules for some interconnections, government policies slowing down the deployment of onshore renewables despite their tumbling costs, and the existing plans for the closure of the remaining coal stations, urgent consideration must be given to ensure supply, energy efficiency and flexibility from now on.

Onshore and offshore renewables need to be at the heart of the future system. This would be good for the environment and competitiveness, as the last few years have seen a remarkable change in economics of renewable energy and it is now recognized that by 2020 electricity from renewables will be ‘within the fossil fuel-fired cost range, with most at the lower end or undercutting fossil fuels’ and are already significantly lower than the current prices offered for nuclear new build. (7 http://www.no2nuclearpower.org.uk/wp/wp-content/uploads/2018/06/SafeEnergyNo78.pdf